Air conditioning apparatus



31, 940- G. METZGER ET AL 2,227,359

AIR CONDITIONING APPARATUS Filed Feb. 15, 1959 Mo EY Hea'l. Generaior Patented Dec. 31, 1940 UNITED STATES AIR. CONDITIONING APPARATUS George Metzger, Russell R. Gannon, and Ludwig Jensen, Cincinnati, Ohio Application February 15, 1939, Serial No. 256,604

5 Claims.

This invention relates to an air conditioning system and more particularly to a method and apparatus for independently controlling various portions of such a system.

An object of the invention is to provide a heating-cooling system so arranged that each room of a building will have its own independently operable thermostat and air conditioning unit, wherein the units in each room comprise part of a larger, building encompassing system.

A further object of the invention is to provide an air conditioning system in which the heating media is positively circulated and supplied to each heat transfer unit in response to a heat demand by any one of said heat transfer units.

Still a further object is to provide an electrical system for controlling the various units of the system comprising the invention.

These and other objects are attained by the means described herein and disclosed in the accompanying drawing, in which:-

Fig. 1 is a diagrammatic representation of a typical air conditioning system embodying the present invention.

Fig. 2 is a schematic wiring diagram of the system disclosed in Fig. 1.

It has long been customary to circulate suitable heating fluids through suitable heat transfer devices such as radiators and grilles and to dissipate the heat from said heat transfer devices by means of fans which force a current of air through or over said heat transfer devices. However, when hot water is the media used to heat the heat transfer device, said device is too rapidly cooled by the current of air blown over its coils with the result that although hot water is an economical heat distributing medium, the prior art devices do not develop such systems to the possible maximum efficiency. It is to obviate this disadvantage that this invention is primarily directed.

As shown in Fig. 1, a typical multi-room set up comprises a plurality of rooms or chambers A and B which are tobe air conditioned. In each room a wall thermostat l and a unitary heat transfer device and blower II is provided. Suitable heat media is generated in a suitable boiler l2 which may, if desired, be located in a basement room C. The various heat transfer devices II are connected in parallel to boiler I2 by means of suitable riser and return pipes l3 and [4 as well known to the art. A suitable electrically driven hot water pump I5 is interposed in series with said riser line, adjacent boiler H as shown.

able radiator or coil l6 through which hot water is forced under pressure by means of pump IS. A fan assembly l1 mounted to the. rear of said radiator or coil is adapted to blow or force air past said coils whereby to transfer the coil heat 5 to the room via the circulating air. The boiler, piping, unit radiator I I, fan I! and thermostat.

l0, may all be of standard parts.

Reference is now made to Fig. 2 for a description of the electrical circuits embodied in said 10 system.

A constant source of electrical energy, such as main lead wires 20 and 2| is utilized to operate the control system. The desired temperature is maintained in any particular room as A orB by means of a suitable thermostat In which controls the individual room blower circuits as well as the hot water pump circuit I5. One side of each blower motor. I! is electrically connected to power line 2| by means of conductor 22, binding post 23 and conductor 24. The blower motor circuit is completed through conductor 25, multi-speed motor switch 26, conductor 2l'to binding post 28, conductor 29, bi-metallic thermostat arm 30,

thermostat contact members 3| or 32, which are speed switch choke coil hookup will be easily recognized by those skilled in the art.

The electrical circuit to water pump l5 comprises conductor 4| electrically connected directly to main line 2|, the other portion of said circuit being connected to binding post 45 of relay unit I50 through conductor 42 to master pump control conductor 43 and conductor 44.

Electrical energy from conductor 20 is supplied to binding post 45 when armature 46 of relay I is pulled down upon contact arm 41 about a suitable hinge 48 in response to energization of coil 45 Hill which is energized by reason of the operation of thermostat H] which places said coil I00 across power lines 20 and 2|. In this manner, the circuit to the motor of water pump [5 is completed, or closed simultaneously with the closing 50 of any blower fan motor circuit. The electrical circuit to said pump motor will remain closed so long as thermostat arm 30 contacts either of contact points 3| or 32, of any of the various room.

thermostats. However, only the blower circuit of '55 the particular room, the thermostat of which is completing an electrical circuit, will be energized.

It is to be understood that the relay unit I50, choke coil 34, multiple speed switch 26 and blower unit I! may all be housed within a suitable cabinet unit indicated by the broken lines 48. Heat transfer unit I6 is likewise housed within said cabinet adjacent blower unit I1 as heretofore explained.

It should be noted that by reason of the electrical circuits described, the blower unit for each room is individually controlled and that each time the circuit of any blower unit motor is closed the electrical circuit to the motor of water pump I5 is likewise closed whereby to circulate hot water through each and every heat transfer unit of the system. It should be understood that the heating of each room is eifected by reason of room air being blown over the heat transfer unit coils and not by reason of radiation from said heat transfer units. By reason of this fact, the temperature of a room already at a predetermined temperature, will not be increased by reason ,of the circulation of hot water through its heat transfer unit when pump I5 is set in operation by the demand for heating fluid in some other room. In this manner the heat dissipated in any single room is independent of the conditions and heat demands existing in other rooms, although the heat transfer units in each room are mutually dependent upon the single source of heat supply, viz., boiler l2 and pump unit I5, the motor circuit of which is adapted to be closed by the thermostat of each room.

Inoperation the system functions as follows: The heating media, water, is constantly maintained at a suitable temperature in boiler I2, and although a certain amount of hot water will circulate through the riser and return pipes l3 and 0 I 4, respectively, due to the convection currents set up within the mass of hot water, the circulation relied upon for the purpose of heating the heat transfer units is dependent upon the motor driven water pump I5.

5 Assume now that the temperature in room A 60 side of bi-metallic arm 3?).

falls below thetemperature setting of thermostat II]. This results in bi-metallie arm contacting; say contact tap M, which instantly closes the electrical circuits to blower unit I! of room A and at the same instant the electrical circuit to the motor of water pump I 5 is closed whereby hot water is circulated through each heat transfer unit. If heat is not needed in room B, the blower unit for that room remains inoperative and the heat being supplied to its coils l5 due to the operation of pump I5 is not dissipated into said room.

It should be noted that two contact taps BI and ,32 are provided in thermostat Ill, one on either In this manner the system just described, may be adapted or converted into a room cooler for summer use by using the rig t tap 32 as the summer heat contact; as well understood in the art. When the 65 blower units are used to cool a room, switch 49 in pump circuit conductor H may be opened as indicated by the broken line 50 for disconnecting pump- I5 from the system.

'Itshould be understood that any number of similar units may be operated from the system disclosed. The multi-speed blower switch 26 is used in order to make the system more flexible, and by enabling a smaller coil I5 to be used in the heat transfer device, the size, cost and weight 750i the room units are materially reduced. By

passing greater or lesser quantities of air over coils I6, more or less heat is delivered from the unit, said quantities of air being directly proportional to the speed of said blower fan IT.

If desired, outside air may be circulated by blower fans Il' during the summer months, by providing suitable ducts in communication with the outside of the building, and located at each of the individual units.

It should be understood that water pump I5 may be placed in the return line I4, if desired, in lieu of the riser line I3 as shown.

Likewise various other modification and changes in the structural details of the device may be made, within the scope of the appended claims, without departing from the spirit of the invention.

What is claimed is:

1. In a control system comprising a plurality of individual heat exchange units each including blower means and individual motors for operating each blower means, each heat exchange unit connected in parallel to a common source of heat supply, heat media recirculating means in series with said source of heat supply, and a motor for operating said means, each blower motor energized by an individual circuit, said recirculating motor being energized by a separate circuit, a separate thermostatic switch responsive to the temperature of the area heated by a heat exchange unit for opening and closing each blower motor circuit, each thermostatic switch being in series with the recirculating motor circuit, means to supply electric current to all circuits, the circuit to the recirculating motor being closed each time any individual blower motor circuit is closed.

2. A control system for a plurality of individual, independently operable blower motors and a single pump motor operable whenever any blower motor is in operation and comprising a three wire electrical system, two of said wires electrically connected to a constant source of electrical energy, each of said blower motors being in one of a plurality of identical series circuits, comprising a blower motor, .an electric automatic circuit closing means responsive to a predetermined temperature of the area .under the influence of its blower, a relay unit, and .electric current control means, .each of said blower motor circuits being connected in parallel across the two wires electrically connected to said constant source of electrical ene gy, said pump motor being electrically connected in series between one wire of said constant source of electrical energy and said third wire, means for electrically connecting the second electrical supplywire to said third wire for completing an electric circuit to said pump motor when any of said blower motor circuits are completed, said means comprising an armature contact arm in a series circuit with said second electrical supply wire and said third Wire and adapted to close said circuit when saidarmature contact arm is actuated by energization of its associated relay unit whereby the circuit to said pump motor is completed simultaneously with the completion of any of the individual independent blower motor circuits.

3. In a multiple zone heating system, the combination of a common source of heat supply, a single fluid conduit system for conveying a heat media from the common source of heat supply to each of a plurality of zones and returning the heat media to the source of heat supply, a single electric motor driven impeller means operatively associated with the fluid conduit system for circulating the heat media therethrough, a plurality of heat transfer units located one in each of a plurality of zones, each heat transfer unit connected in parallel to the fluid conduit system, a plurality of electric motor driven air circulating means operatively associated one each with each heat transfer unit, a plurality of electric automatic switching means responsive one each to the temperature of a separate one of said zones for controlling the operation of the air circulating means for that zone and for simultaneously controlling the operation of the impeller means for the entire fluid conduit system.

4. A three wire electrical control system for a multiple zone heating system comprising in combination a plurality of heat transfer units located one in each of a plurality of zones, electric motor driven air circulating means associated with each heat transfer unit, a common source of heat media, a closed heat media conduit system, each heat transfer unit connected in parallel in the heat media conduit circuit, a single electric motor driven heat media impeller means for circulating the heat media through the heat transfer conduit system, of a plurality of duplicate electrical circuits for controlling one each the operation of one air circulating means, each of said duplicate circuits comprising an electric automatic switch means responsive to predetermined temperatures of a separate one of said zones and being in series with the air circulating means of that zone, each of said duplicate circuits being connected in parallel across a two wire power line, said power line being electrically connected to a constant source of electrical energy, said heat media impeller motor connected in series with one power line and the third wire of the three wire system, said third Wire adapted to be electrically connected to the second wire of the power line upon energization of any air circulating means circuit whereby the heat media impeller motor is operated continuously and simultaneously with the operation of any air cir culating motor.

5. A control system comprising a plurality of individual heat exchange units, blower means associated with each heat exchange unit, individual motors for driving each blower means, a closed heat media circuit, a common heat media circulating means for distributing heat media to all of the heat exchange units, a motor for driving said heat media circulating means, an individual electrical circuit for controlling the operation of each blower motor, a common electrical circuit for controlling the operation of the circulation motor, a thermostatically controlled electric switch means controlled by an external condition for controlling the operation of each of said blower motors and for concurrently controlling the operation of the circulator motor.

GEORGE METZGER. RUSSELL R. GANNON. LUDWIG JENSEN. 

